||This article may be too technical for most readers to understand. (April 2014)|
|Classification and external resources|
Mucormycosis is any fungal infection caused by fungi in the order Mucorales.:328 Generally, species in the Mucor, Rhizopus, Absidia, and Cunninghamella genera are most often implicated. This disease is often characterized by hyphae growing in and around vessels.
Also, while Zygomycosis includes Entomophthorales, mucormycosis excludes this group.
Signs and symptoms
Mucormycosis frequently involves the sinuses, brain, or lungs as the areas of infection. While oral or cerebral mucormycosis are the most common types of the disease, this infection can also manifest in the gastrointestinal tract, skin, and in other organ systems. In rare cases, the maxilla may be affected by mucormycosis. The rich vascularity of maxillofacial areas usually prevents fungal infections, although more virulent fungi, such as those responsible for mucormycosis, can often overcome this difficulty.
There are several key signs which point towards mucormycosis. One such sign is fungal invasion into the blood vessels which results in the formation of blood clots and surrounding tissue death by loss of blood supply. If the disease involves the brain, then symptoms may include a one-sided headache behind the eyes, facial pain, fevers, nasal congestion that progresses to black discharge, and acute sinusitis along with swelling of the eye. Affected skin may appear relatively normal during the earliest stages of infection. This skin quickly becomes reddened and may be swollen before eventually turning black due to tissue death. Other forms of mucormycosis may involve the lungs, skin, or be widespread throughout the body; symptoms may also include difficulty breathing, and persistent cough. In cases of tissue death, symptoms include nausea and vomiting, coughing up blood, and abdominal pain.
If mucormycosis is suspected, amphotericin B therapy should be immediately administered due to the rapid spread and high mortality rate of the disease. Amphotericin B (which works by damaging the cell walls of the fungi) is usually administered for an additional 4–6 weeks after initial therapy begins to ensure eradication of the infection. Posaconazole has been shown to be effective against mucormycosis, perhaps more so than amphotericin B, but has not yet replaced it as the standard of care. A liposomal formulation of amphotericin B is also available, but this drug is very expensive.
Surgical therapy can be very drastic, and in some cases of Rhinocerebral disease removal of infected brain tissue may be required. In some cases surgery may be disfiguring because it may involve removal of the palate, nasal cavity, or eye structures. Surgery may be extended to more than one operation. It has been hypothesized that hyperbaric oxygen may be beneficial as an adjunctive therapy because higher oxygen pressure increases the ability of neutrophils to kill the organism.
In most cases, the prognosis of mucormycosis is poor and has varied mortality rates depending on its form and severity. In the rhinocerebral form, the mortality rate is between 30% and 70%, whereas disseminated mucormycosis presents with the highest mortality rate in an otherwise healthy patient, with a mortality rate of up to 90%. Patients with AIDS have a mortality rate of almost 100%. Possible complications of mucormycosis include the partial loss of neurological function, blindness and clotting of brain or lung vessels.
Mucormycosis is a very rare infection, and as such it is hard to note histories of patients and incidence of the infection. However, one American oncology center revealed that mucormycosis was found in 0.7% of autopsies and roughly 20 patients per every 100,000 admissions to that center. In the United States, mucormycosis was most commonly found in rhinocerebral form, almost always with hyperglycemia and metabolic acidosis. In most cases the patient is immunocompromised, although rare cases have occurred in which the subject was not; these are usually due to a traumatic inoculation of fungal spores. Internationally, mucormycosis was found in 1% of patients with acute leukemia in an Italian review.
In the U.S. it is not required of all hospitals to report hospital-acquired disease to the public or patients, and details of a lethal outbreak in 2008, emerged in 2014 after television and newspaper reports responded to an article in a pediatric medical journal. Contaminated hospital linen was found to be spreading the infection.
A cluster of infections occurred in the wake of the 2011 Joplin tornado. As of July 19, a total of 18 suspected cases of cutaneous mucormycosis had been identified, of which 13 were confirmed. A confirmed case was defined as 1) necrotizing soft-tissue infection requiring antifungal treatment or surgical debridement in a person injured in the tornado, 2) with illness onset on or after May 22, and 3) positive fungal culture or histopathology and genetic sequencing consistent with a Mucormycete. No additional cases related to that outbreak have been reported since June 17. Ten patients required admission to an intensive-care unit, and five died.
Cutaneous mucormycosis has been reported after previous natural disasters; however, this is the first known cluster occurring after a tornado. None of the infections were found in persons cleaning up debris; instead it is believed transmission occurred through penetrating injuries inflicted by contaminated objects (e.g. splinters from a woodpile). Health-care providers should consider environmental fungi as potential causes of necrotizing soft-tissue infections in patients injured during tornados and initiate early treatment for suspected infections.
Predisposing factors for mucormycosis include AIDS, diabetes, malignancies such as lymphomas, renal failure, organ transplant, long term corticosteroid and immunosuppressive therapy, cirrhosis energy malnutrition, and Deferoxamine therapy. Despite this, however, there have been cases of mucormycosis reported with no apparent predisposing factors present.
Notable people affected
- James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
- Rinaldi M.G. (1989). "Zygomycosis". Infect Dis Clin North Am 3: 19–41.
- Lee F.Y.; Mossad S.B.; Adal K.A. (1999). "Pulmonary mucormycosis: the last 30 years". Arch Intern Med 159: 1301–9. doi:10.1001/archinte.159.12.1301. PMID 10386506.
- Staff Springfield News-Leader (10 June 2011) "Aggressive fungus strikes Joplin tornado victims" Seattle PI, Hearst Communications Inc.
- Nancy F Crum-Cianflone, MD MPH. "Mucormycosis". eMedicine. Retrieved 2008-05-19.
- Auluck A (2007). "Maxillary necrosis by mucormycosis. a case report and literature review" (PDF). Med Oral Patol Oral Cir Bucal 12 (5): E360–4. PMID 17767099. Retrieved 2008-05-19.
- Spellberg B, Edwards J, Ibrahim A (2005). "Novel perspectives on mucormycosis: pathophysiology, presentation, and management". Clin. Microbiol. Rev. 18 (3): 556–69. doi:10.1128/CMR.18.3.556-569.2005. PMC 1195964. PMID 16020690.
- "MedlinePlus Medical Encyclopedia: Mucormycosis". Retrieved 2008-05-19.
- Rebecca J. Frey, PhD. "Mucormycosis". Health A to Z. Retrieved 2008-05-19.
- Roden MM, Zaoutis TE, Buchanan WL, et al (September 2005). "Epidemiology and outcome of Mucormycosis: a review of 929 reported cases". Clin. Infect. Dis. 41 (5): 634–53. doi:10.1086/432579. PMID 16080086.
- "Mother believes her newborn was the first to die from fungus at Children's Hospital in 2008".
- "5 Children's Hospital patients died in 2008, 2009 after contact with deadly fungus". "We acknowledge that Children's Hospital is Hospital A in an upcoming article in The Pediatric Infectious Disease Journal. The safety and well-being of our patients are our top priorities, so as soon as a problem was suspected, the State Health Department and CDC were notified and invited to assist in the investigation. The hospital was extremely aggressive in trying to isolate and then eliminate the source of the fungus."
- Rare Infection Strikes Victims of a Tornado in Missouri
- MMWR Weekly July 29, 2011 / 60(29);992
- Joplin outbreak publication: NEJM 2012 Dec 6; 367:2214